I am sorry for your loss and that you had to raise kids on your own. But, I don't think you should be resentful towards men that may have passed you over. I imagine plenty of women would have some reservations of getting involved with a man with 5 kids of his own. That is a lot of extra responsibility to walk right into, fair or not. I hope your family and friends helped you raise your kids and they turned out well.
To answer your question, yes, it probably goes beyond fertility. Men are visual creatures. That is just the way it is. But things may be changing a bit... did you read all the posts about "cougars?"
I have 6 kids of my own, mostly already raised, but if a man was interested in me and had a bunch of kids and was raising them in a Godly way, I'd be more than ready! Bring them on!!